Curtin University

About: Curtin University is a education organization based out in Perth, Western Australia, Australia. It is known for research contribution in the topics: Population & Zircon. The organization has 14257 authors who have published 48997 publications receiving 1336531 citations. The organization is also known as: WAIT & Western Australian Institute of Technology.

Instagrammatics and digital methods: Studying visual social media, from selfies and GIFs to memes and emoji

Abstract: Visual content is a critical component of everyday social media, on platforms explicitly framed around the visual (Instagram and Vine), on those offering a mix of text and images in myriad forms (Facebook, Twitter, and Tumblr), and in apps and profiles where visual presentation and provision of information are important considerations. However, despite being so prominent in forms such as selfies, looping media, infographics, memes, online videos, and more, sociocultural research into the visual as a central component of online communication has lagged behind the analysis of popular, predominantly text-driven social media. This paper underlines the increasing importance of visual elements to digital, social, and mobile media within everyday life, addressing the significant research gap in methods for tracking, analysing, and understanding visual social media as both image-based and intertextual content. In this paper, we build on our previous methodological considerations of Instagram in isolation ...

Origin and age of the earliest Martian crust from meteorite NWA 7533

Abstract: Chemical analysis of the meteorite NWA 7533 indicates that it may be a Martian regolith breccia and, if so, that the crust of Mars may have formed in the first 100 million years of the planet’s history. This paper identifies the NWA 7533 meteorite from Northwest Africa as the first sample of Martian highlands rock in the meteorite collection. Munir Humayun and co-authors show that NWA 7533 has a composition indicative of a highlands breccia. It also contains zircons more than 4.4 billion years old, implying that early crustal differentiation on Mars occurred in the first 100 million years of its history, coeval with earliest crust formation on the Moon and the Earth. The ancient cratered terrain of the southern highlands of Mars is thought to hold clues to the planet’s early differentiation1,2, but until now no meteoritic regolith breccias have been recovered from Mars. Here we show that the meteorite Northwest Africa (NWA) 7533 (paired with meteorite NWA 70343) is a polymict breccia consisting of a fine-grained interclast matrix containing clasts of igneous-textured rocks and fine-grained clast-laden impact melt rocks. High abundances of meteoritic siderophiles (for example nickel and iridium) found throughout the rock reach a level in the fine-grained portions equivalent to 5 per cent CI chondritic input, which is comparable to the highest levels found in lunar breccias. Furthermore, analyses of three leucocratic monzonite clasts show a correlation between nickel, iridium and magnesium consistent with differentiation from impact melts. Compositionally, all the fine-grained material is alkalic basalt, chemically identical (except for sulphur, chlorine and zinc) to soils from Gusev crater. Thus, we propose that NWA 7533 is a Martian regolith breccia. It contains zircons for which we measured an age of 4,428 ± 25 million years, which were later disturbed 1,712 ± 85 million years ago. This evidence for early crustal differentiation implies that the Martian crust, and its volatile inventory4, formed in about the first 100 million years of Martian history, coeval with earliest crust formation on the Moon5 and the Earth6. In addition, incompatible element abundances in clast-laden impact melt rocks and interclast matrix provide a geochemical estimate of the average thickness of the Martian crust (50 kilometres) comparable to that estimated geophysically2,7.

Past and present distribution, densities and movements of blue whales Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean

Abstract: 1. Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of 8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. 2. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2%) or pairs (24.6%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. 3. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. 4. Compared with historical catches, the Antarctic (‘true') subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. 5. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic blue whales. 6. South-east Pacific blue whales have a discrete distribution and high sighting rates compared with the Antarctic. Further work is needed to clarify their subspecific status given their distinctive genetics, acoustics and length frequencies. 7. Antarctic blue whales numbered 1700 (95% Bayesian interval 860–2900) in 1996 (less than 1% of original levels), but are increasing at 7.3% per annum (95% Bayesian interval 1.4– 11.6%). The status of other populations in the Southern Hemisphere and northern Indian Ocean is unknown because few abundance estimates are available, but higher recent sighting rates suggest that they are less depleted than Antarctic blue whales.

Drivers of Corporate Social Responsibility: the Role of Formal Strategic Planning and Firm Culture

Abstract: Scholars have paid considerable attention to studying the relationship between corporate social responsibility (CSR) and firm performance. Yet, little empirical research demonstrates what actually shapes or drives CSR. This paper builds a case that formal strategic planning is one such driver in that it creates awareness of and formulates responses to stakeholder demands for CSR. However, exploring single variable relationships is problematic, as other important endogenous factors need to be considered in explaining CSR. Specifically, firm culture is identified as influencing a firm’s orientation towards the responsible treatment of stakeholders. One such cultural factor, humanistic culture, is argued to have a positive effect on CSR. By studying a sample of heterogeneous firms in Australia, results demonstrate that a formal strategic planning effort is positively linked to CSR. Further, a humanistic culture positively impacts CSR, after accounting for a firm’s formal planning efforts.

Intercomparison of shallow water bathymetry, hydro‐optics, and benthos mapping techniques in Australian and Caribbean coastal environments

Abstract: Science, resource management, and defense need algorithms capable of using airborne or satellite imagery to accu rately map bathymetry, water quality, and substrate composition in optically shallow waters. Although a variety of inver sion algorithms are available, there has been limited assessment of performance and no work has been published com paring their accuracy and efficiency. This paper compares the absolute and relative accuracies and computational effi ciencies of one empirical and five radiative-transfer-based published approaches applied to coastal sites at Lee Stocking Island in the Bahamas and Moreton Bay in eastern Australia. These sites have published airborne hyperspectral data and field data. The assessment showed that (1) radiative-transfer‐based methods were more accurate than the empirical approach for bathymetric retrieval, and the accuracies and processing times were inversely related to the complexity of the models used; (2) all inversion methods provided moder ately accurate retrievals of bathymetry, water column inher ent optical properties, and benthic reflectance in waters less than 13 m deep with homogeneous to heterogeneous benth ic/substrate covers; (3) slightly higher accuracy retrievals were obtained from locally parameterized methods; and (4) no method compared here can be considered optimal for all situ ations. The results provide a guide to the conditions where each approach may be used (available image and field data and processing capability). A re-analysis of these same or addi tional sites with satellite hyperspectral data with lower spatial and radiometric resolution, but higher temporal resolution would be instructive to establish guidelines for repeatable regional to global scale shallow water mapping approaches. Optically shallow waters, those where the bottom is visible from the water surface and measurably influences the waterleaving radiance, include inland waters through to estuarine and tropical coral reef and temperate coastal ecosystems. Over